After thinking about this observation, it brought to mind the writings of Jonathan Haidt and his work "The Righteous Mind". This work is nicely summarized in 2011 article in Scientific American (Link)
"To understand what constitutes these moral matrices Haidt teamed with Craig Joseph from the University of Chicago. Building on ideas from the anthropologist Richard Shweder (with whom they both had studied), they developed the idea that humans possess six universal moral modules, or moral "foundations," that get built upon to varying degrees across culture and time. They are: Care/harm, Fairness/cheating, Loyalty/betrayal, Authority/subversion, Sanctity/degradation, and Liberty/oppression. Haidt describes these six modules like a "tongue with six taste receptors." "In this analogy," he explains in the book, "the moral matrix of a culture is something like its cuisine: it’s a cultural construction, influenced by accidents of environment and history, but it’s not so flexible that anything goes. You can’t have a cuisine based on grass and tree bark, or even one based primarily on bitter tastes. Cuisines vary, but they all must please tongues equipped with the same five taste receptors. Moral matrices vary, but they all must please righteous minds equipped with the same six social receptors."It may appear that he is thoroughly unprincipled but that is not the case. Trump values loyalty beyond all other principles. His earlier dealings with Jim Comey provides support for this. Recall that in his initial dealings with Comey what he asked for ( LA Times link)
President Trump demanded "loyalty" from former FBI Director James B. Comey and asked him to drop at least part of the bureau's investigation of former National Security Adviser Mike Flynn, Comey plans to testify to Congress Thursday. In a prepared statement posted on the Senate Intelligence Committee website, Comey says that in a private dinner with Trump on Jan. 27, the president asked him if he wanted to remain as head of the FBI and told him “I need loyalty, I expect loyalty.”"I didn’t move, speak, or change my facial expression in any way during the awkward silence that followed. We simply looked at each other in silence," Comey says. He told Trump that he could promise "honesty," he says.Comey did not get it. To Trump, loyalty is much more important than honesty. Trump's mind is likely equipped with all of the same six social receptors, but he applies a different emphasis on particular receptors. Haidt showed that this differential emphasis is a characteristic of people with certain patterns of emphasis associated with particular political leanings. One can take a test to see where your individual leanings might be and which moral senses you might emphasize at (http://www.yourmorals.org/). Haidt has noted that liberals and conservatives tend to place emphasis on different priorities, where liberals placing great emphasis on care and fairness and conservatives placing more emphasis on sanctity, authority, and loyalty. Surprisingly, there seems to be an inherited component to this differential weighting that goes beyond environment. Thus, our moral intuitions may be driven by genetics to some degree.
Although I realize this is rank speculation, I believe if Donald Trump took this test his results would be skewed toward a single minded emphasis on loyalty. His focus on loyalty is so strong and so single minded, it is hard for the rest of us to comprehend. Yet, it does seem to explain what otherwise defies explanation. Donald Trump becomes quite understandable once you realize that no other principles are in play.